Heavy duty pneumatic tires for use on trucks, buses, etc., are expected to have traction performance under various road surface conditions. In order to meet such expectations, a heavy duty pneumatic tire generally includes a tread surface on which land portion blocks or rib-shaped land portions are defined, for example, by circumferential-direction grooves that extend along a tread circumferential line and narrow width-direction grooves that extend in a tread width direction (refer to PTL 1 for example).